Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D303/00—Compounds containing three-membered rings having one oxygen atom as the only ring hetero atom
  • C07D303/02—Compounds containing oxirane rings
  • C07D303/38—Compounds containing oxirane rings with hydrocarbon radicals, substituted by carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals
  • C07D303/40—Compounds containing oxirane rings with hydrocarbon radicals, substituted by carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals by ester radicals
  • C07D303/42—Acyclic compounds having a chain of seven or more carbon atoms, e.g. epoxidised fats
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D301/00—Preparation of oxiranes
  • C07D301/02—Synthesis of the oxirane ring
  • C07D301/03—Synthesis of the oxirane ring by oxidation of unsaturated compounds, or of mixtures of unsaturated and saturated compounds
  • C07D301/14—Synthesis of the oxirane ring by oxidation of unsaturated compounds, or of mixtures of unsaturated and saturated compounds with organic peracids, or salts, anhydrides or esters thereof
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D301/00—Preparation of oxiranes
  • C07D301/02—Synthesis of the oxirane ring
  • C07D301/03—Synthesis of the oxirane ring by oxidation of unsaturated compounds, or of mixtures of unsaturated and saturated compounds
  • C07D301/14—Synthesis of the oxirane ring by oxidation of unsaturated compounds, or of mixtures of unsaturated and saturated compounds with organic peracids, or salts, anhydrides or esters thereof
  • C07D301/16—Synthesis of the oxirane ring by oxidation of unsaturated compounds, or of mixtures of unsaturated and saturated compounds with organic peracids, or salts, anhydrides or esters thereof formed in situ, e.g. from carboxylic acids and hydrogen peroxide
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D303/00—Compounds containing three-membered rings having one oxygen atom as the only ring hetero atom
  • C07D303/02—Compounds containing oxirane rings
  • C07D303/04—Compounds containing oxirane rings containing only hydrogen and carbon atoms in addition to the ring oxygen atoms
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D303/00—Compounds containing three-membered rings having one oxygen atom as the only ring hetero atom
  • C07D303/02—Compounds containing oxirane rings
  • C07D303/12—Compounds containing oxirane rings with hydrocarbon radicals, substituted by singly or doubly bound oxygen atoms
  • C07D303/14—Compounds containing oxirane rings with hydrocarbon radicals, substituted by singly or doubly bound oxygen atoms by free hydroxyl radicals

Definitions

• the invention relates to a multi-stage process for the continuous epoxidation of double bonds end and internal olefins with more than 12 carbon atoms, unsaturated fatty acids and their esters and unsaturated alcohols with 8 to 18, preferably 18, carbon atoms in the alkyl radical and triglycerides, preferably soybean oil, with hydrogen peroxide and formic acid in the presence of a catalyst.
• the quality of the olefinic starting material and the corresponding epoxides is essentially determined by two key figures, namely the iodine number (IZ) and the epoxy value (EPO). While the iodine number is a measure of the number of unsaturated double bonds, the epoxy value indicates the percentage (weight percent) of epoxy oxygen; it is therefore a measure of the epoxy yield. The higher the epoxy value and the lower the iodine number, the better the quality of the epoxy.
• soybean oil epoxide For example, a very good quality soybean oil epoxide is characterized by IZ ⁇ 2.5 and EPO ⁇ 6.5, with good quality values of IZ ⁇ 5.0 and EPO ⁇ 6.3 are achieved. Soybean oil epoxide with an iodine number above 5.0 or an epoxy value below 6, 3 is considered to be inferior in application technology. The goal of an epoxidation process must therefore be to produce epoxy that has both a low iodine number and a high epoxy value.
• the density of the heavier aqueous phase decreases as the reaction progresses, while the density of the oily phase increases.
• the difference in density between the phases becomes very small, which separates the phases by gravity separation sword.
• the heat generated in the separator during epoxidation results in convection currents as a result of temperature gradients, which are amplified by rising gas bubbles which form when the aqueous phase decomposes.
• cross-countercurrent method it was nevertheless possible to achieve good phase separation by gravity separation. Concentrations are achieved in each reaction stage, which ensure a sufficiently large density difference between the aqueous and oily phases for phase separation.
• the deposition is further promoted by fillers made of glass or ceramic.
• the invention accordingly relates to a multi-stage process for the continuous epoxidation of double bonds of terminal and internal olefins with more than 12 carbon atoms, unsaturated fatty acids and their esters and unsaturated alcohols with 8 to 18, preferably 18 carbon atoms in the alkyl radical and triglycerides, preferably soybean oil , using performic acid formed in situ on hydrogen peroxide and formic acid, which is characterized in that the reactants olefin and hydrogen peroxide / formic acid in an at least 3-stage, preferably 4-stage, reaction cascade, the individual stages of which consist of a stirred tank reactor and a phase separator Ambient pressure in cross-counterflow leads, the olefin phase being metered into the first reaction stage, the hydrogen peroxide and the formic acid in separate streams to the penultimate reaction stage, and the olefin and hydrogen peroxide / formic acid phase (acid water phase) in each re Action level after off emerges from the reactor in a phase
• the olefinic phase runs through the number of reaction stages in increasing order from I to n.
• the reactants hydrogen peroxide and formic acid
• the main addition point is in the reactor of the stage (n-1).
• the acid water phase is led to reaction stage I via the nth stage.
• the hydrogen peroxide and / or the formic acid stream is divided up on reactors of stages II to (n-1).
• a post-reaction vessel downstream of the nth stage is not counted as an independent reaction stage, since no phase separator belongs to this unit.
• each separator has two built-in, independently operated heat exchangers for cooling the olefin-containing and the aqueous phase.
• the watery Phase is kept as cold as possible in order to avoid decomposition losses of hydrogen peroxide and formic acid and not to impair the separation of the aqueous phase from the olefin-containing phase by ascending CO 2 bubbles, which arise during the decomposition of the performic acid.
• the aqueous phase is cooled to a temperature of 15-40 ° C, preferably 20 ° C.
• the density difference between olefin-containing and aqueous phases decreases with falling temperature, the mixture of homogeneous olefin-containing phase and disperse aqueous phase in the separator must not be cooled too much.
• the temperatures in the olefin-containing phase are therefore between 30 and 60 ° C and thus up to 30 ° C lower than the reactor temperature of the corresponding stage. This also prevents an uncontrolled subsequent reaction that starts at 50 - 70oC depending on the concentration conditions.
• the hot reaction mixture emerging from the reactor is fed to the separator below the phase boundary. It rises due to the density difference and flows through the cold aqueous phase, where it cools down and the reaction is stopped. In addition, when the aqueous phase flows through, part of the acid water is already separated from the reaction mixture.
• the separation of the phases in the cross-countercurrent process enables a system circuit with which, in comparison with the discontinuous process, higher epoxy yields can be achieved with the same excess of H 2 O 2 or the same epoxy yields with a lower excess of H 2 O 2 .
• the addition of the Re Action partners takes place in such a way that an imperfect separation of the phases due to the solubility of hydrogen peroxide and formic acid in the olefin-containing phase does not lead to acid water losses.
• Each stage has a stirred tank as reactor 1, 3, 5, 7 and 9, in which the reaction takes place in the liquid phase.
• the mixture of partially epoxidized olefin, hydrogen peroxide, formic acid, water and catalyst emerging from the reactor is separated in separator 2, 4, 6 and 8 into an aqueous phase consisting of hydrogen peroxide, formic acid, water and catalyst, and an olefinic phase, Consists of an epoxidized olefin corresponding to the respective reaction stage and dissolved or dispersed portions of the aqueous phase.
• the olefinic and the aqueous phase are then fed to the reactors at different stages (solid or broken lines).
• the reaction partner containing olefinic double bonds is added in reactor 1. Then it passes through the separators and reactors in the order of increasing numbers from 2 to 9. In reactor 5, 70% hydrogen peroxide is metered in together with the catalyst and 85% formic acid.
• the aqueous phase passes through the reactors and Ab separators in the order 5 - 6 - 3 - 4 - 7 - 8 - 1 - 2.
• the highly concentrated acid water dissolved and carried along in the separator 6 in the olefin phase is washed out of the separator 4 in the reactor 7 with the low-concentration aqueous phase and then after separation of the olefin-containing phase in the separator 8 fed to the reactor 1.
• the temperatures in the reactors are kept constant by indirect cooling and are 50 to 80 ° C, preferably 70 ° C, in reactors 1, 3, 5 and 7; in the after-reaction container 9 the temperature is 40 to 60 ° C, preferably 50 ° C.
• the average residence time per reactor is 1.5 to 2 hours in reactors 1, 3, 5 and 7 and 3-8 hours in the after-reaction tank 9.
• the separators have the same usable volume as that
• the dwell time of the aqueous phase should be as short as is possible for design reasons in order to avoid decomposition losses and to be able to quickly compensate for transient operating fluctuations, such as those which occur when the system is started up, for example.
• the temperatures of the mass flows fed to the reactors are lower than the corresponding reaction temperatures, ie the reactors are partially cooled by the quantity flows and thereby relieve the cooling systems of the reactors.
• the use of a catalyst is completely possible.
• the catalysts known for in-situ epoxidation such as sulfuric acid or phosphoric acid, can be used to shorten the residence time.
• HEDP hydroxyethane-1,2-diphosphonic acid
• the flow of materials is shown schematically in FIG. 2.
• 10.9 kg / h (1.1 mol / mol double bond (DB)) 70% hydrogen peroxide and 1.88 kg / h (0.17 mol / mol DB) 85% formic acid added.
• 0.1 kg / h of hydroxyethane-1,2-diphosphonic acid were added to the H 2 o 2 feed stream.
• the oil phase and the aqueous phase were cooled separately so that the temperature of the oil phase was about 45 ° C and that of the aqueous phase was 20 ° C.
• the reaction was carried out in all reactors at 70 ° C.
• a soybean oil epoxide with an epoxy oxygen content of 6.47% and an iodine number of 5.6 was obtained.
• the acid water left the plant with a hydrogen peroxide concentration of 6.2% by weight.
• Example 2 was carried out as in Example 1, but with an additional post-reaction vessel of 300 1 usable volume, in which the double bonds still present were reacted further with constituents of the aqueous phase dissolved and dispersed in the olefin phase at a temperature of 50 ° C. (FIG. 3) .
• the epoxy value rose to 6.55 and the iodine number was reduced to 2.8.
• Example 2 Compared to Example 2, the use of H 2 O 2 was increased to 11.9 kg / h (1.2 mol / mol DB) and the formic acid according to FIG. 4 was divided into the second and third stages, so that in the second stage 0 , 03 mol / mol DB and in the third stage 0.14 mol / mol DB were metered in.
• the reactor temperature of the fourth stage was reduced to 60 ° C; all other temperatures corresponded to those of Example 2.
• the epoxy obtained had an epoxy value of 6.62 and an iodine number of 2.2.
• Example 5 (comparative example):
• the material flows were carried out in counterflow according to FIG. 5.
• the amounts used and the temperatures of the reactors and separators corresponded to those of Example 1.
• the hydrogen peroxide in the aqueous phase was reduced to 5.0% by weight, the epoxy had only an epoxy value of 6.03 with an iodine number of 8.2 , because part of the highly concentrated acid water in the fourth stage was discharged through the oil phase due to incomplete phase separation.
• the soybean oil used was epoxidized in a four-stage direct current cascade (no separators) (FIG. 6).
• the amounts used were 40 kg / h soybean oil, 11.9 kg / h (1.2 mol / mol DB) 70% hydrogen peroxide, 1.88 kg / h (0.17 mol / mol DB) 85% formic acid and 0 , 1 kg / h of hydroxyethane-1,2-diphosphonic acid. All reaction components were metered in in the first stage and then went through stages II, III and IV.
• the reactors were identical to those in Example 1.
• the reaction temperature was 70 ° C. in all reactors.
• Ocenol R (an unsaturated fatty alcohol of chain length C16 / 18 with an iodine number of 88.3) was epoxidized in a five-stage mixer-settler system as shown in FIG. 7.
• the reactors and separators each had a useful volume of 100 l.
• the amounts used were 60 kg / h of unsaturated fatty alcohol, 15.2 kg / h (1.5 mol / mol DB) 70% hydrogen peroxide, 4.52 kg / h ( 0.4 mol / mol DB) 85% formic acid and 0.14 kg / h hydroxyethane-1,2-di ⁇ hosphonic acid, which was added to the hydrogen peroxide.
• the use of hydrogen peroxide was divided into the third and fourth stages, and the use of formic acid into the second and third stages.
• the reaction was carried out at 70 ° C in stages I to IV and at 60 ° C in stage V.
• the olefin phase was cooled to 50 ° C and the aqueous phase to 20 ° C.
• the epoxy produced in this way had an epoxy value of 4.1 with a residual iodine number of 2.1, which corresponded to a yield of 77.8% and a conversion of 97.6%.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Epoxy Compounds (AREA)

Priority Applications (2)

Applications Claiming Priority (1)

Publications (1)

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ID=6200644

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Country Status (6)

Cited By (3)

Families Citing this family (14)

Citations (2)

• 1983
  • 1983-06-03 DE DE19833320219 patent/DE3320219A1/de not_active Withdrawn
• 1984
  • 1984-05-25 EP EP84902203A patent/EP0144387B1/de not_active Expired - Lifetime
  • 1984-05-25 DE DE8484902203T patent/DE3481417D1/de not_active Expired - Fee Related
  • 1984-05-25 JP JP59502243A patent/JPS60501457A/ja active Granted
  • 1984-05-25 WO PCT/EP1984/000160 patent/WO1984004920A1/de active IP Right Grant
  • 1984-05-30 US US06/615,446 patent/US4584390A/en not_active Expired - Fee Related
  • 1984-06-01 IT IT21209/84A patent/IT1176229B/it active

Patent Citations (2)

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